CLX v.15 and User-Defined Data Type Online Edits

A while ago I heard that v.15 of CLX will allow Online Edits of user-defined data types. Can anyone confirm or deny that?

n_lev said:

A while ago I heard that v.15 of CLX will allow Online Edits of user-defined data types. Can anyone confirm or deny that?

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I have never seen that. Any time I had to insert or delete a field within a UDT it as always been offline then down loaded. Here is a snip from the new features readme file with Logix 5K



Ian

Thanks, Ian!

I definitely heard it from someone. Guess the person was just dreaming about good future

You cannot currently edit UDT's online. In fact I am not sure you will ever be able to. Allowing unlimited UDT edit's is a very big ask in terms of what the processor is required to do. A simple rename of a member would be easy enough to achieve, but it doesn't stop there, because there is no innate limit to what can be edited online. In essence unlimited UDT edits is asking the Logix CPU to fully recompile the program while at the same time keeping all the logic running. It does not strike me as a simple thing to do.

However at V15 what you can do is download a new UDT structure and create new tags of that type while online.

Sorry Phillip, but I disagree with you. You can edit a UDT online in version 15 but only if it is not used for a tag. I know this is not a lot of help to most people as the UDT is mostly used.
BUT there is a work around. Takes a while but is better than nothing.
Say you have a UDT called ABC and a tag of data type ABC called XYZ.
Make an identical UDT called ABC_1 and create a new tag called XYZ_1. Now online edit and replace all XYZ tags with XYZ_1 tags.
(you will have to use a few brains doing this to do things in the correct order, ie add additional outputs, then inputs then delete existing inputs and outputs)
When XYZ is not used then delete the tag.
Now that the UDT of ABC is not used then you can alter it to what you want. Now create the tag XYZ again and do the reverse swap.

If you are not worried about a different tag name and UDT name then just create a new UDT online, make a new tag and intelligently replace them.
I know this is a long winded way but in a process that cannot be shut down it is do-able.
Regards Alan Case

Thank you Alan. Yes I've been doing something similar to what you have outlined, but I guess I just didn't think of it in the same terms as you.

At this point I still think it is correct to say that you cannot online edit a UDT structure, IF there are any existing tags using that structure.

The workaround you describe can be quite useful, but as you say it can be a little long-winded and you need to keep your wits about you.

More usefully what I do is include in all my larger UDT structures as smaller child UDT that I call <Spare> which consists of a something like:

BOOL[32], INT[16], DINTS[32] and REAL[32] (Or whatever suits your fancy)

These are then automatically created as a member of the parent UDT and are available as "Spare" tags to be used for online editing. Usually you don't need a lot of them, but having a few already created makes for very easy additions.

Then whenever I have the chance to do a download I just seach on the child <Spare> datatype names and change them to permanent names within the UDT parent. Very neat and tidy. (No prize for guessing where I picked up this dodge from Alan

Thanks phillip. I will have to remember that one.
Regards Alan Case

I hope New UDT can be created online, it can be deleted/modify when it is not refered any data table

I create spare elements too. I wish I could say that I am religous about replacing them with permenent elements later.

I have used Alan's method as well.

Yes, you can create a UDT online. You can create it, edit it, and delete it online as long as no tags of that data type exist.

RSL